for 32 years, now retired baltimore city officer jim snyder tried to do all the little things right. >> i stopped him. >> reporter: even in the biggest story of his career. >> to help stop a killer. >> reporter: the video may seem dated now, but the memory of that month back in 2002 is far from faded. ten people killed, three critically injured. the targets as unsettling as the act. gas stations, buses, schools. the dc sniper paralyzed life inside and out two beltways putting evything in life on hold. >> you had to live through it to appreciate what we had gone through that day, just to get gas. >> reporter: snyder didn't just live through it, he worked it. he chased his fair share of white box trucks and misguided jbut it ^where he would find the devil. >> a chevy caprice parked at this gas station blocking the door where he knew the restaurant got its delivery. the windows fogged, clothes piled up in the back even what he thought was a rusted out hole in the trunk. the time 2:30 in the morningment >> you didn't think much of it? >> no. just a random stop. i ran all checks humanly